Aha, that's the problem. I hit something similar before. What version/build of esxi are you using? Basically, you need a version of diskLibCertTool that matches to version of your ESX. The latest Workbench is suppose to include many different versions of diskLibCertTool.
My testbed is base on older build of esxi, so I have an older workbench build, so I don't have the files you are looking for. Try to grab the latest workbench again, or you might have to switch to a different esxi build...
